Chamber for three-dimensional positioning of fragrances without dispersion
The study of the human olfactory system has progressed rapidly in recent years. However, when architects use fragrance in spatial designs, they tend to do so merely for branding purposes or for suggestive advertising (e.g. pumping the smell of coffee out onto a street to attract people into a store). Such designs fail to pick up on the potentials for developing evocative and memorable experiences using the sense of smell. This project demonstrates how smell can be used spatially to create fragrance collages that form soft zones and boundaries that are configurable on-the-fly.
Airflow within the space is generated by an array of fans. Moving air is then controlled by a series of diffusion screens to provide smooth and continuous laminar airflow. Computer-controlled fragrance dispensers and careful air control enable parts of the space to be selectively scented in slow moving 'cubes' without dispersing through the entire space.
Sited in UCL’s main Portico, the Scents of Space chamber was a simple translucent enclosure that glowed inwardly during the day and outwardly at night. Visitors entered the chamber and experienced carefully controlled zones of fragrance that defined and demarked areas of space without physical boundaries, encouraging people to encounter an invisible yet tangible smell environment.
Each of the dozen smells can be precisely and dynamically located in three-dimensional space, allowing visitors to encounter new scent boundaries as they move along the horizontal and vertical axes of the interaction zone. Smells are emitted in response to people’s movements and these smells travel slowly through the space in straight lines until the visitors choose to mingle the fragrances with the movement of their bodies.
Movement inside the enclosure triggers smells, either singly or in 'chords', to build up fragrance 'paintings' of alternative environments, such as the odours of a city street or the scents of a mountainside forest. Smells travel slowly through the space in straight lines until visitors choose to mingle the scents with their bodies.
The fragrances used in the chamber are both pleasant and unpleasant; recognisable and unfamiliar; natural and artificial. The odourants are created by dissolving single molecules (for single “notes”) in alcohol. These odourants are then released into air streams, where the alcohol evaporates to leave clearly discernible fragrances.
In the first version of the installation, constructed at UCL in 2002, we used a fragrance ensemble we named Strangely Familiar, consisting of synthesised odourants - garlic, pineapple, blackcurrant, mushroom, grapefruit, apple, truffle/leek, pop corn, coriander, supplied by Oxford Chemicals.
In other versions, other fragrance ensembles were employed, including Urban Sprawl - fragrances evoking a journey through a city, including a metro, a garden, a coffee shop, a bus stop, a laundromat; and Rose Garden - the individual scents of several types of rose.
In terms of technical apparatus, moving air is controlled by a series of diffusion screens, in pressure chambers, to provide smooth and continuous laminar airflow. Computer-controlled fragrance dispensers selectively scent parts of the airflow, so that when the air enters the interaction space the smells remain within their own particular zone.
The air in the interaction space moves at a speed of 0.2 m/s – this is slow enough that visitors don’t feel the movement of the air but are merely aware of the smells appearing and disappearing as they move past. As each smell is emitted from the Smell Wall, the zone from which it comes lights up to indicate that the smell has been activated in that area.
There are two levels of interaction in the Scents of Space installation.
The primary interaction occurs between the space and the visitors - scents are output in response to the position and movements of people. The system builds up a database of responses to smell, from which it develops strategies for being either “alluring” or “repelling”. In this way, the installation is constantly evolving in its responses to the movement patterns of visitors.
A secondary level of interaction occurs between the visitors and the smells themselves. Visitors movements mingle conjoining smells to create turbulent “third” smells. In this way, the space is actually passively reacting to the visitors’ movements. At the same time, visitors build up a pattern of associations and memories, because smell is so closely linked to the ability to recollect experiences of space.
Visitors remember other spaces while in the installation; they also remember the installation when they encounter similar fragrances once they’ve left the installation.
Smell is powerful and effective at defining a place. Physiologically it is deeply connected to memory and experience; emotionally it is inseparable from instinct and association. However, of the five human senses, architects, designers and builders tend to ignore its potential as an important part of the spatial palette.
If an architectural space could be precisely “tuned” with scents, it would be possible to create highly evocative and memorable experiences. Smell and temperature work together to alter our perception and therefore definition of a space - its size, its “openness”, and its intimacy. For example, highly volatile scents (such as the smell of cut grass) travel further and tend to evoke feelings of expanse, whereas less volatile scents (such as musks) tend to suggest closer proximity. We can track a similar range of experiences using temperature - from a cool emptiness, via a warm coziness to a hot claustrophobia. Since volatility is closely related to temperature, a wide variety of spatial experiences can be suggested within similarly configured environments.
We use all kinds of conscious and unconscious cues to help us get from A to B. We normally think of these as visual cues, however, our olfactory perception is also used in navigation and often reinforces these visual cues. Decisions about which route to take through a space might be influenced by, for example, our knowledge that the smell of smoke implies “danger” or the smell of freshly baked bread is “desirable”. Olfactory “landmarks” could be designed to delineate sectors of an environment in a more conscious and deliberate way, while olfactory “paths” could reinforce specific routes through a space.
We have all experienced the ways in which smell plays a crucial role in memory triggering. Whether it is a fragrance from one’s childhood or the scent of a favourite cafe, it immediately evokes what it was like to be in that remembered place. Sometimes smells remind us of a specific event; other times they conjure up a general “ambience”. Though little is known about how this happens, we can utilise the associative nature of olfactory stimuli to make the experience of a place more memorable.
Vent-Axia generously supplied fans and control equipment for the Scents of Space chamber. Oxford Chemicals and International Flavours and Fragrances supplied smell sources. Max Fordham provided design advice for air movement and control.